1. Big Era One
Humans in the Universe
13 Billion – 200,000 Years Ago

2. 2
Where did
our Earth
come from?
How did
the universe
come to be?
How & when
did we humans
appear on Earth?

3. All peoples have explanations of our origins.
The Maidu people, native to California, say
that Earth Starter made the world from
some green slime Turtle brought up from
deep underwater. He made humans from
red earth mixed with water.
3
… And the Chinese
used to say that
Phan Ku – no thing,
not yet born – burst
from a hen’s egg and
became the Great
Creator.

4. 4
Scientists offer a different explanation, based on
evidence gathered from sources on earth and in
space. Here’s what they might say:
Long ago, there was no time...
There was no space...
But 13 billion years ago..
things changed.

5. 5
BANG!

6. 6
Where there had been
nothing, now there was
everything. The whole
universe – tiny, and
fantastically hot.
For an instant, it
expanded faster than the
speed of light. Then it
slowed down but kept
expanding, as it still is.

7. 7
As the universe cooled down,
clouds of hydrogen and
helium gas began to gather
together, their centers
getting hotter and hotter.
Big
Bang
13bilyrsago
Big Era 1
Big
Eras
2-9

8. 8
And when they
were hot enough, the
hydrogen atoms began
to fuse together with
the power of millions of
hydrogen bombs.

9. 9
As a result…
STARS
WERE BORN!

10. 10
They clustered together
in vast galaxies, each
containing billions of
these new stars.
I can’t
see us
yet...
Stars &
Galaxies
12 bil yrs ago
Big
Bang
13bilyrsago
Big Era 1
Big
Eras
2-9
Big Era 1Big Era 1

11. 11
Four and a half billion years
ago – when the universe
was already two-thirds as
old as it is today – a star
was born near the edge of a
galaxy we call the Milky
Way:
OUR SUN!
Our Sun &
Planets
4.6 bil yrs ago
Big
Bang
13bilyrs
ago
Big Era 1
Big
Eras
2-9
Stars&
Galaxies
12bilyrs
ago

12. 12
Around the sun, wisps of matter were drawn together by the
forces of gravity to create the planets of our solar system…

13. 13
…Including the third
rock from the sun:
OUR EARTH!
What aWhat a
cute baby,cute baby,
huh?huh?

14. 14
The early earth was
incredibly HOT.
Heavier metals melted
and sank to the center,
lighter metals rose to
the surface, and gases
bubbled up to make the
earth’s first
atmosphere.
Anybody got
something for
a stomach
ache?

15. 15
By four billion years
ago, the earth had
cooled enough for
water to condense into
oceans. And so the
earth turned blue.
The surface hardened
into thin “plates”
floating on the molten
materials underneath.
Those “plates” float on
the surface to this day,
constantly changing the
landscapes and weather
patterns on the earth’s
surface.

16. 16
Where the plates collided, great
mountains were formed...

17. 17
...and where they tore
apart, melted rock
poured out from under
the surface.

18. 18
Deep within the newly
formed oceans,
complex chemicals
were created using
volcanic heat for
energy.
Some of these
chemicals became so
highly organized that
they formed cells – the
first LIFE ON EARTH!
First
Life
3.8 bil
yrs ago
Big
Bang
13bilyrsago
Big Era 1
Big
Eras
2-9
OurSun
&Planets
4.6bilyrsago
Stars&
Galaxies
12bilyrsago

19. 19
Living organisms changed
the atmosphere, adding
oxygen. Cells developed
that could “breathe”
oxygen...

20. ...and, about 600 million
years ago, the first multi-
cellular organisms arose
in the earth’s oceans.
Big Era 1
3.8bilyrs
ago
FirstLife
Big
Bang
13bilyrsago
OurSun
&Planets
4.6bilyrs
ago
Stars&
Galaxies
12bilyrsago
Multi-Celled
Organisms
600m
yrs ago
Big
Eras
2-9

21. 21
The first animals appeared
not too long after!

22. 22
After a while, some
animals moved out of the
oceans and onto the land.
First Life
on Land
400m
yrs ago
FirstLife3.8bilyrsago
250kyrsago
Today
Scale of Life on Earth
Big
Eras
2-9
Multi-Celled
Organisms600myrsago

23. 23
Dinosaurs were the most
successful of the early
land animals...
First
Dinosaurs
220m yrs ago
FirstLife
onLand
400myrsago
250kyrsago
Today
Scale of Life on Land
Big
Eras
2-9

24. 24
...but about 65 million
years ago, a giant
meteor came crashing
down to earth...
...and the dinosaurs
were no more!
Dinosaurs Disappear
67m yrs ago
First
Dinosaurs
220myrsago
FirstLife
onLand
400myrsago
250kyrsago
Today
Scale of Life on Land
Big
Eras
2-9

25. 25
MAMMALS!
This left a new class of animals dominant on the land.

26. Over time, a particular group of
mammals emerged that lived in
trees.
To survive in that environment,
these mammals needed 3D vision
and large brains to process visual
information. They also needed
hands that could grip with
precision. (Imagine living in a tree
without any of these. You’d fall
out!)
These mammals were the first
PRIMATES.
26

27. Then, about 7 million years ago in Africa, a
branch of those primates became the first to
stand upright.
These were the first HOMINIDS. Different
hominids lived on earth over the next 7 million
years, some at the same time as others, but only
one survives to this day...
US!!!
27

28. First
Hominids
7m yrs
ago
The earliest hominids
lived in small, family-
sized groups. They
gathered plants, insects,
and small animals, and
they occasionally
scavenged the meat of
larger animals killed by
predators.
Dinosaurs
Disappear
67myrsago
250kyrsago
Today
Scale of Life after the Dinosaurs
Big
Eras
2-9

29. 29
4 – 1.5m yrs ago
Australopithecines
7myrsago
First
Hominids
250kyrsago
Today
The first hominids had
brains about the size of
a modern chimp’s. Over
time, new species
developed ever-larger
brains, and they began
to make more and more
complex tools. The
Australopithecines
likely used sharp sticks
to dig for food...
Big
Eras
2-9

30. 30
Homo habilis
2.4 – 1.6m yrs ago
250kyrsago
Today
4myrsago
Australopithecines
1.5myrsago
Big
Eras
2-9
...while Homo habilis
hominids, a later
species, were able to
make stone tools. They
chipped ‘flakes’ of
stone from large rocks
and used those flakes
as knives. They also
used the leftover ‘core’
to scrape out hides and
do other jobs.

31. 31
250kyrsago
Today
4myrsago
Australopithecines
1.5myrsago
Homo habilis
2.4myrsago
1.6myrsago
Big
Eras
2-9
Homo erectus hominids,
which lived on Earth for
almost two million
years, were probably
the first ones who could
control and use fire.
They were also
the first to leave Africa.
Their fossils have been
found as far away as
China and Java (in
modern Indonesia).
Homo erectus
1.8m – 27k yrs ago

32. 32
Social relationships
among our ancestors
were complex. Like
modern chimpanzees,
early hominids must
have been quite clever,
with a great deal of
social cooperation and
group politics. They
cared for each other,
especially their children.
WOW! These
early ancestors
of ours sound a
lot like us!

33. 33
Well, in some ways
that’s true – but this
species was different in
many other respects
from our species. We
have no evidence, for
example, that they had
art, religion, or
language.
ART RELIGION LANGUAGE

34. 34
So, what’s so
special about
us? What
makes us
HUMAN, and
how did we
BECOME
human?

35. 35
End of Big Era One
Well, you’ll just
have to wait for
BIG ERA TWO to
get the answer to
those questions!